1. Field of the Invention
The present invention relates to an improved liquid dispensing apparatus, more specifically, a dispenser with a valve assembly having an unrestricted fluid path, and an overall greater area of flow capacity through the dispenser valve. More specifically, the present invention is for a liquid dispenser wherein the dispenser valve incorporates an elevated streamlined spring seat stand-off and a funnel shaped chamber.
2. Background Art
Liquid and semi-liquid dispensers are used in numerous applications and are used to dispense metered portions of cremes, lotions, soaps, and similar materials. A typical dispenser allows the user to obtain a specific amount of liquid matter with minimal ease. Manual and automatic dispensing systems are common in the industry.
The manual dispensers utilize levers and other mechanical assemblies wherein the user must provide some physical contact with the unit in order to dispense the liquid. Automatic dispensers are becoming increasingly popular, and operate with a variety of electrical and electro-mechanical components to automatically dispense the liquid after triggering some sensory input. Once the sensor mechanism is triggered, a mechanical means is still required to force out a metered quantity of liquid.
Within the field of liquid dispensers, there are many types of dispensers. The most common and cost effective is the bag-in-box system, wherein the liquid comes in a no-leak pouch with a pump tip and is disposable when no liquid remains in the pouch. This system is a closed system, and all the air is removed from the pouch during manufacturing. The bag collapses upon itself once the liquid is evacuated, minimizing waste disposal. The closed system has many advantages, including being a more sanitary system. The standard size pouch is 800 ml, but other sizes are in use, including 1000 ml and 1200 ml, and larger sizes are possible, as they are more economical to operate. It is a necessary requirement that the cost to produce a bag-in-box system be kept to a minimum, while still delivering consistent results. These dispensers are installed in many public facilities and are subject to extreme wear and tear, thus they must also be robust and relatively maintenance-free. As a disposable unit, if the bag-in-box system malfunctions, the system is thrown out along with any remaining liquid in the pouch.
Other dispensers use cartridges or re-fillable containers. The cartridges must be pierced, are generally not refillable, and produce greater waste. Both cartridges and refillable containers introduce air into the system, aiding the production of bacteria and mold. The cost and administrative complexity in using these other forms of dispensers, as well as the decreased sanitary condition limits their market appeal. Regardless of the type of housing for the liquid, whether pouch, canister, cartridge or container, the liquid must still be dispensed through a dispenser valve assembly.
The liquid soap industry has numerous brands and categories of soaps. The viscosity and particulate content are also subject to extreme variations. There is an array of particulate matter that can be added to liquid soaps to form a grit soap compound that is more effective in cleaning. The most common grit material is plastic microspheres, although other materials such as clay, walnut shells and corn cobs have also been used. Besides the variations of compounds used to form grit soap, the size of the grit also varies.
There are several lines of liquid soaps with synthetic particles, namely plastic balls, that constitute grit compounds. The size of the particulate varies, and a series of products include Microgrit 40, Microgrit 60, and Microgrit 70. The increased consumer demand for grit in liquid soaps has led to an increase in malfunctions in existing dispensers.
There has also been a consumer demand for antimicrobial soaps, and the industry has reacted by adding creating new compounds with anti-bacterial properties. These antimicrobial soaps are available with or without grit and have certain characteristics and viscosity differences as compared to standard liquid soap.
Besides liquid soap, other compounds that are used in liquid dispensers include body and hair shampoo, hand creme solutions, lotion soaps, and shaving creme. Any flowable liquid is capable of being dispensed. Prior art designs are generally not effective in dispensing viscous liquids.
In a typical bag-in-box operation, a user depresses a lever or controller. This applies pressure to the liquid in the collapsible pouch that exerts fluid pressure against the ball in the ball check valve. If the pressure is sufficient, the ball is displaced, and the liquid flows around the ball and into the ball check valve chamber. The liquid flows into the space between the spring and the interior wall of the ball check valve chamber. Once the chamber is sufficiently full, the liquid is forced through the compressed spring and out through the lower fitment hole and through the nozzle.
Many of the current dispensers cannot adequately handle the grit, grit compounds, or viscous liquids. The dispenser valves have a narrow point or restricted passage that limits the size of the particulate matter that can pass freely and generally impedes viscous liquids. In most cases, this narrow area is directly before the exit nozzle, at the spring seat.
A common problem with most bag-in-box dispensers is that the dispenser valve tends to clog and become unusable after a number of manipulations. Once the pump tip becomes clogged, the entire pouch and pump tip is normally thrown out, regardless of the amount of liquid remaining in the pouch. The expenditure in time and materials is significant due to the number of dispensers in the market.
In order to reduce the aforementioned problems, attempts have been made to produce an efficient and cost-effective dispensing system. The prior art systems have general short-comings and do not adequately address or correct these problems.
The pump tip in U.S. Pat. No. 5,501,372 is an improved tip design, but as shown in FIG. 5, the liquid has a limited exit point that restricts the liquid flow. The spring contacts the flush spring seat, creating a bottleneck in the dispensing process. The liquid is substantially forced through the center of the spring in order to exit out of the nozzle tip. In addition, the flat surface of the spring seat provides a surface for collecting debris and otherwise facilitating clogging of the nozzle, especially when particulate matter is mixed with the liquid.
U.S. Pat. No. 4,130,224 is another dispensing apparatus, wherein the ball check valve is held in place by a spring, with the spring seat perpendicular to the spring, as illustrated in FIG's 3, 4, 5, and 6. When the lever is pressed, the fluid is compressed, creating a pressure that exceeds the spring tension. The ball is forced away from the ball seat and fluid flows around the ball and into the inner chamber. The exit nozzle is smaller in dimension than the diameter of the inner chamber, and the spring seat is on the upper end of the exit nozzle, with the spring contacting the spring seat. The liquid must go through the spring to exit the nozzle.
A similar ball check valve is disclosed in FIG. 5 of U.S. Pat. No. 4,394,938 ('938), wherein the '938 invention depicts the arrangement of the ball contacting the ball seat, and held in place by the spring. The spring is perpendicular to the spring seat, which is a substantially flat surface. When the ball is displaced from the ball seat, the liquid is forced around the ball. The path of the liquid is primarily down the cross sectional area outside the spring until the liquid contacts the flattened surface of the spring seat, where the liquid is then forced to exit through the center of the spring.
A similar ball check arrangement is shown in FIG. 10 of U.S. Pat. No. 4,515,294. The spring is retained within a tube, and a smaller diameter inner tube forms the lower end of the spring seat. Once the ball is displaced from the ball seat, the liquid flow is obstructed and must be diverted through the center of the spring before it enters the inner tube. In yet another dispenser device, U.S. Pat. No. 4,722,372 in FIG. 7 shows the spring seat flush and perpendicular to the spring as in previous examples.
U.S. Pat. No. 4,621,749 shows another ball check valve, where the lower end of spring chamber has a slight angle at the lower portion as shown in FIG. 10. However, the liquid must still flow around the spring in order to exit the cavity. In addition, the location of the angle is at a point where the flow is already restricted. Another example of an angled portion is shown U.S. Pat. No. 5,265,772 in FIG. 9. In both these figures, the bottom coil was not flat, but was angled like the other coils and seated in the chamber accordingly. Neither discloses nor suggests any significance relating to fluid flow characteristics, and neither discusses or infers any advantages to angled chamber design or elevated standoffs.
A different valve dispensing assembly is illustrated in U.S. Pat. No. 4,143,853, wherein a rubber disc with a slit is used as the means of gating the liquid flow. In operation, the normally closed slit is opened when a force is applied to the edges of the disc by the engaging assembly located on the outer periphery of the disc. In this invention, the planar seat surfaces are required in order to function properly. This invention is specifically intended for use as a catheter. U.S. Pat. No. 4,394,938 employs a similar design, wherein a slit diaphragm is used as the gating mechanism for dispensing metered portions.
Another design is disclosed in U.S. Pat. No. 4,607,764, where an elastomeric band functions as the check valve and allows a metered portion of liquid to be dispensed. This invention creates a flow channel by having specific openings and indents within which the fluid passes.
What is needed is a dispenser pump tip design that eliminates restriction and obstructions in the liquid flow. Such a design should allow greater cross sectional flow into the nozzle. This design would eliminate the need for the liquid to be forced to enter the spring center, and should greatly increase the flow capacity of the dispenser. An additional feature of such a design would be the ability of the dispenser to handle grit products and viscous liquids, and reduce the clogging evident in present designs. This design must also be cost effective to manufacture and implement, and allow for easy incorporation into current dispenser designs.